Isophthalic add

Hundreds of different carboxylic acids have been produced via this method (1), The industrial process, dubbed the Amoco MC process, produces billions of pounds of terephthalic add, isophthalic add and trimellitic add annually. Industrial processes using just cobalt as the catalyst rather than Co/Mn/Br have also been developed (2-3). The characteristics of the reaction suggest that it is, at least partially, a free radical chain mechanism involving peroxy... 

Figure 3. Photoisomerization of isophthalic add copolyamide uAth 4,4 -diamino-diphenylsulfone and 4,4 -diaminoazobenzene...

Copolymers of fumaric acid or maleic anhydride and isophthalic add were prepared by melt condensation at 250-300 °C for 8 hours using acetic anhydride or polyphosphoric acid as dehydrative agents [43]. 

The present method for preparing aromatic dicarboxylic adds has been used to convert phthalic or isophthalic add to tereph-thalic acid (90-95%) 2,2 -biphenyldicarboxylic acid to 4,4 -biphenyldicarboxylic add 3,4-pyrroledicarboxylic acid to 2,5-pyr-roledicarboxylic add and 2,3-pyridinedicarboxylic acid to 2,S-pyridinedicarboxylic acid. A closely related method for preparing aromatic dicarboxylic adds is the thermal disproportionation of the potassium salt of an aromatic monocarboxylic acid to an equimolar mixture of the corresponding aromatic hydrocarbon and the dipotassium salt of an aromatic dicarboxylic acid. The disproportionation method has been used to convert benzoic acid to terephthalic acid (90-95%) pyridine-carboxylic adds to 2,5-pyridinedicarboxylic acid (30-50%) 2-furoic add to 2,5-furandicarboxylic acid 2-thiophenecar-boxylic add to 2,5-thiophenedicarboxylic acid and 2-quinoline-carboxylic acid to 2,4-quinolinedicarboxylic acid. One or the other of these two methods is often the best way to make otherwise inaccessible aromatic dicarboxylic acids. The two methods were recently reviewed. ... 

Isophthalic add is produced by only a small number of companies in the USA (Amoco% Japan Mitsubishi Gas Chemical) and Italy Sisas). Its main use is in the production of unsaturated polyester resins. It yields polyesters of greater strength and higher resistance to corrosion than those derived from phthalic add. 

Other uses are in the production of alkyd resins, although isophthalic acid has no noticeable advantage over PA. However, during the 1960 s, there was a shortage of PA in the USA for a time, and isophthalic add was used as a substitute, despite its higher cost. 

Isophthaloyl chloride is an industrially important derivative of isophthalic add. It is produced by chlorination (SOCI2/CI2) of m-xylene via the intermediate l,3-bis-(trichloromethyl)-benzene and its reaction with isophthalic add. Iso-phthaloylchloride, along with m-phenylenediamine, serves as a monomer component for the production of the high-strength and heat-resistant aramid fiber Nomex Du Pont),... 

Phthalic acid anhydride (o-xylene), isophthalic add (m-xylene) terephthalic add (p-xylene)... 

Rauwolscine gires colour leactions like those of yohimbine and the absorption curves of the hydrochlorides of the two alkaloids are very similar. Heated to 300°j5 mm. rauwolscinic acid forms barman (p. 490) and 3-ethylindole and on fusion with potassium hydroxide decomposes into indole-2-carboxylic acid, isophthalic add, barman and an unidentified indole derivative.. Rauwolsdne itself on distillation with zinc dust produces barman, 2-methylindole (scatole) and isoquinoline. It is suggested that the alkaloid has the skeletal structure suggested by Scholz (formula XIV, p. 508) for yohimbine, the positions of the hydroxyl and carbomethoxy groups being stUl undetermined. 

The guest molecules include coronene (COR), a large triangular aromatic hydrocarbon (Figure 6.2), " a giant wheel-like molecule with a diameter of 5.7 nm, and a heterocluster formed by coronene and isophthalic add. ... 

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